HDTV Buying Guide - Full HD vs HD ReadyHigh Definition TeleVision (HDTV) is a digital television broadcasting system with higher resolution and better sound system than standard television systems (NTSC, SECAM, PAL). The most obvious difference is HDTV uses a widescreen aspect ratio of 16:9 as compared to standard TV which uses a aspect ratio of 4:3.To enjoy HDTV programs, you need to get a HD Ready or Full HD TV set as well as a DTV-T setup box.with broadcastingdefinitiondigitalhdtvhighersystemtelevisionunsorted